MINNEAPOLIS (WCCO) – Personal behavior led to the downfall of General David Petraeus. But so did emails. A FBI investigation into email led them to the affair. The situation has many wondering about when and who can have access to our emails.

When can the FBI read our email? When can your boss read your email?

Former FBI Special Agent Scott Larson is now the President of Larson Security, a digital forensics firm advising Fortune 500 companies.

“It is scary. I don’t think people understand how much is available on their daily conversations,” Larson said.

The 1986 Electronic Communications Privacy Act is the U.S. law that governs how law enforcement gets access to our computers and our electronic data.

Is the government actively monitoring our email?

‘No. Not everybody’s email. But for certain criminal investigations and national security situations, they are monitoring email,” Larson said.

The law sets up three paths for police and the government to read your email:

1) You could agree to share it.

2) A search warrant from a judge for recent emails.

3) Or a subpoena for emails older than 180 days.

“It’s fairly easy [to get a subpoena]. You discuss the case with a prosecutor,” Larson said.

It’s not like they can access anybody’s email for no reason, though.

“It has to be a criminal investigation or a national security case, and it has to go through a prosecutor,” he said.

As far as email at work, we use it quite a bit. One report estimates we send an average of 35 emails a day at work, and receive 75 more.

Obviously, our employer has the right to look through any of our work emails. But what about Gmail or Hotmail accessed through our work computers?

“That is not private and it can be recorded through web tools. Or it can be recovered from a hard drive,” Larson said.

He said most workplaces don’t have the manpower to monitor every email sent by employees, but some industries are more aggressive than others.

“Definitely in financial securities. And they have a regulators requirement to monitor certain conversations, chats and emails, and that’s being recorded all the time,” Larson said.

Of course, avoiding affairs is the easiest way to avoid having your email be a problem.

“You better behave, or you don’t know what’s going to happen,” Larson said. “If you don’t want it on the top page of the newspaper, don’t put it in email.”